marty obama will take the official oath of office. it's a private ceremony being held at the white house. as mandated by the constitution. new video in this morning shows the president and vice president joe biden at a wreath laying ceremony at arlington national cemetery. but tomorrow. the big celebration happens. a second, public swearing in ceremony. which we will carry live. there have been a thousand details for organizers to consider. here's kron four's catherine heenan with more. >> catherine: a few facts about how these crowds will be handled. the u.s. military will be helping park police for the first time ever. the secret service will be working with 57 federal and local agencies. a new app is designed to keep people from getting lost or stuck in overcrowded spots -- which happened in 2009. there's continued concern over whether there will be enough porta-potties. also - a new pastor has been chosen to give the benediction. unlike the first choice - luis leon supports same sex marriage. the estimated cost - about 40-million